#3600 AD global catalog discovery not functionning
Closed: worksforme 6 years ago Opened 6 years ago by chrisv.

========= Configs =====
CentOS 7.4.1708 (Core)
SSSD: 1.15.2-50
python-sssdconfig-1.15.2-50.el7_4.8.noarch
libsss_autofs-1.15.2-50.el7_4.8.x86_64
sssd-ipa-1.15.2-50.el7_4.8.x86_64
sssd-dbus-1.15.2-50.el7_4.8.x86_64
sssd-1.15.2-50.el7_4.8.x86_64
libsss_certmap-1.15.2-50.el7_4.6.x86_64
libsss_idmap-1.15.2-50.el7_4.8.x86_64
sssd-client-1.15.2-50.el7_4.8.x86_64
sssd-common-1.15.2-50.el7_4.8.x86_64
sssd-common-pac-1.15.2-50.el7_4.8.x86_64
sssd-ad-1.15.2-50.el7_4.8.x86_64
sssd-krb5-1.15.2-50.el7_4.8.x86_64
libsss_simpleifp-1.15.2-50.el7_4.8.x86_64
sssd-proxy-1.15.2-50.el7_4.8.x86_64
sssd-tools-1.15.2-50.el7_4.8.x86_64
libsss_nss_idmap-1.15.2-50.el7_4.6.x86_64
libsss_sudo-1.15.2-50.el7_4.8.x86_64
sssd-krb5-common-1.15.2-50.el7_4.8.x86_64
sssd-ldap-1.15.2-50.el7_4.8.x86_64
python-sss-1.15.2-50.el7_4.8.x86_64

==
Active directory 2016
Domain : subdomain.domain.org
2 domain controllers
DC0001
DC0002
Both DC are acting as DNS, NTP, DC, Global Catalog

Posix attributes have been added into the Global Catalog

Firewall are open (confirmed by telnet on port 3268 / GC port)

The Linux host has been joined in the AD using "realm join"

===

==== Issue ====
When a server is multi-homed, SSSD is unabled to discover the Global Catalog (GC are discovered on server having only one NIC)
Issue persists after one of the Network Interface is removed

While I do not see obvious error in the Debug log, there seems to be some noticeable behavior in the logs (see extract here under)

[sbus_message_handler] (0x2000): Received SBUS method org.freedesktop.sssd.DataProvider.Failover.ListServices on path /org/freedesktop/sssd/dataprovider
[sssd[be[SUBDOMAIN.DOMAIN.ORG]]] [sbus_get_sender_id_send] (0x2000): Not a sysbus message, quit

TCPDUMP indicate that the SSSD client did query the DNS for the AD records (SRV), and that the answers did flag the Global Catalog properly

To reproduce
Setup an AD 2016, with two DC
Add (using Schema Manager) the POSIX attibutes in the GC
Configure the AD default site to list all the subnets involved

Install Centos 
Install Kerberos + SSSD + realm & depencies (from Centos Repos)

Join the domain using realm join

-- Configure krb5.conf & sssd.conf accordingly

# sssctl domain-status SUBDOMAIN.DOMAIN.ORG
Online status: Online

Active servers:
AD Global Catalog: DC0001.subdomain.domain.org
AD Domain Controller: DC0001.subdomain.domain.org

Discovered AD Global Catalog servers:
- DC0001.subdomain.domain.org
- DC0002.subdomain.domain.orga

Discovered AD Domain Controller servers:
- DC0001.subdomain.domain.org
- DC0002.subdomain.domain.org
========

Add a second interface
setup the interface with a valid IP

Re-run sssctl
# sssctl domain-status SUBDOMAIN.DOMAIN.ORG
Online status: Online

Active servers:
AD Global Catalog: not connected
AD Domain Controller: DC0001.subdomain.domain.org

Discovered AD Global Catalog servers:
None so far.

Discovered AD Domain Controller servers:
- DC0001.subdomain.domain.org
- DC0002.subdomain.domain.org

========

Remove the interface,
Reboot
sssctl domain status will return the same result

==== Last update ===
A second server that never had a second interface shows the same symptoms after SSSD has been restarted.
No changes I'm aware of.

Note: the log supplied have been anynomized, I have been careful to do a constitent substition inluding the case.a
Bug_sssd.zip


Hi, sorry for late reply. We did not have much people around during Christmas. This is not a bug, rather an expected behavior, as far as the provided logs can tell.

SSSD is performing DNS discovery for for both domain controllers and global catalog server on demand. Therefore sssctl will show no servers for either category if such servers were not required so far.

I see successful attempts to disover "AD" service which translates to domain controllers, but none attempt to resolve "AD_GC" service, which means global catalog. If you first give any query that will use global catalog, it should tell you the servers. For example:

id some-user
sssctl domain-status domain

No further comments for one months, therefore I assume the issue is no longer valid and can be closed.

Metadata Update from @jhrozek:
- Issue close_status updated to: worksforme
- Issue status updated to: Closed (was: Open)

6 years ago

SSSD is moving from Pagure to Github. This means that new issues and pull requests
will be accepted only in SSSD's github repository.

This issue has been cloned to Github and is available here:
- https://github.com/SSSD/sssd/issues/4623

If you want to receive further updates on the issue, please navigate to the github issue
and click on subscribe button.

Thank you for understanding. We apologize for all inconvenience.

Login to comment on this ticket.

Metadata
Attachments 1
Attached 6 years ago View Comment